Trump also called the former secretary of defense "a nasty guy" and "an absolute clown." And he said, "I don't like critics."

Earlier Saturday, Trump addressed the Remembrance Project in Houston. That's an organization founded to advocate for tougher immigration laws in honor of those killed by people in the country illegally. Trump says he is "shining a national spotlight" on Americans killed by immigrants living in the United States illegally.

The Republican nominee says "not one more American life should be given up in the name of open borders."